Senate near a coin flip, House at 95 in 100 as Maine tightens

Fifty-three days from the November 3 election, our model gives Democrats a 48 percent chance of winning Senate control and Republicans 51 percent, as of 6:32 AM ET Friday. The mean outcome in our simulations is 50.2 Democratic seats. Democrats need 51 seats for a majority; Republicans need 50, because the vice president is a Republican and a 50-50 tie goes to the Republicans. In the House, our model gives Democrats a 95 in 100 chance of winning control, with a mean of 240.7 seats against the 218 needed.

That House figure carries a caveat of our own making. Our simulation draws error at four correlated levels: one national, one for each census division, one for each state, and one for each district on its own. It does not include a term linking demographically similar districts in different places, because we have no cluster data to build one. The effect is that our House control probability is marginally firmer than a fuller decomposition would leave it. We have not measured the size of that gap for this run, so we are not putting a number on it.

Our generic ballot average is D+6.7, drawn from 24 polls fielded in the past 45 days. Two of the most recent are wider than that. A Quinnipiac University survey of 970 registered voters, fielded September 3-6, had Democrats at 49 percent and Republicans at 38. An Economist/YouGov poll fielded September 4-8 had the same 49-38 split among 1,015 likely voters, and Democrats ahead 42-35 among 1,464 registered voters.

The largest move on the board is in Maine, where our estimate of the Democratic chance fell 28 points, from 89 percent to 61 percent. Three recent surveys have Troy Jackson ahead of Susan Collins: a YouGov poll fielded September 2-8 had Jackson up 48-44 among 1,335 likely voters and 46-44 among 1,378 registered voters, and a CNN/SSRS poll of 880 likely voters, fielded August 31 to September 6, had Jackson at 48 and Collins at 45. Elsewhere, Ohio rose 20.7 points to 68 percent for the Democrat, South Carolina rose 10.1 points to 18 percent, North Carolina rose 7.4 points to 85 percent, and California's 48th District rose 7.1 points to 23 percent. Iowa moved the other way, down 6.8 points to 30 percent.

The state polling behind those numbers is mostly tight. An InsiderAdvantage survey of 1,200 Ohio likely voters, fielded September 8-9, had Sherrod Brown at 47.3 percent and Jon Husted at 41.9. The same pollster, on the same dates and with the same sample size, found close races in Texas, with James Talarico at 47.1 percent and Ken Paxton at 45.6, and in South Carolina, where the Republican stood at 45.1 percent and Annie Andrews at 43.2. A Change Research poll for Freedom Project USA, of 1,107 Florida likely voters fielded September 7-9, had Ashley Moody and the Democrat tied at 47 percent. In Michigan, a Trafalgar Group survey of 1,079 likely voters fielded September 7-9 put Abdul El-Sayed at 46.3 percent and Mike Rogers at 44.8, and CNN/SSRS, polling 843 likely voters, had El-Sayed at 47 and Rogers at 44.